Question

Diketahui f(x) = x² + 2x - 8 dan g(x) = x² + 3x + 2 . Tentukan f(-1) dan (g°f)(-1)

Answer 1

F(x) = x² + 2x - 8
g(x) = x² +3x + 2

f(-1) = (-1)² + 2(-1)  - 8 = -9

(gof)(x)
 = g(f(-1))
 = (x² + 2x - 8)² +3(x² + 2x - 8) + 2
 = ((-1) + 2(-1) - 8)² + 3((-1) + 2(-1) - 8) + 2
 = (-9)² + 3(-9) + 2
 = 81 - 27 + 2
 = 56

Answer 2

Dik:f(x):x²+2x-8
g(x):x²+3x+2
dit:f(-1)
(g°f)(-1)
jawab:*f(-1):(-1)²+2(-1)-8
:1-2-8
=-9
*(g°f)(-1):g(f(x))
:g(-1)
:(-1)²+3(-1)+2
:1-3+2
=0